I was browsing Reddit.com yesterday and noticed this post. User guyanonymous (yes I am really crediting him regardless of his name!) had posted up this string-art picture which has parabolic curves created from straight lines and gave me permission to post it up here on the corkboard. I love the repeating "flower" pattern.

He also linked to this picture in the comments showing other "experiments." If you click on the picture and make it bigger you will see these too are made from straight lines. I really like the final two.